This invention relates to pulsed combustors and more particularly to a thrust augmenting fluid rectifier for a valveless pulsed combustor.
There have been various proposals for providing a valveless pulsed combustor. Applicant's U.S. Pat. No. 3,543,781 describes a valveless rectifier suitable for pulsed combustors.
Although fluid rectifiers are effective in redirecting inlet backflow, they cause pressure losses and reduce the rating, that is, the amount of fuel that can be consumed by a pulsed combustor of given size.
For gas turbines, substantial improvements in performance can be obtained with combustors that provide a pressure gain. However, it has not been possible to provide significant pressure-gain with valveless pulsed combustors. Applicant has obtained modest pressure gain with a valveless pulsed combustor, using a rectifier of the type described in applicant's aforesaid patent, mounted in a duct to provide two stage ejector-like pumping of secondary flow. However, the best result obtained was a stagnation pressure gain of only 0.8%, at a stagnation temperature ratio of 2.5:1. It was found that the main cause of performance loss was the fluid rectifier.